Base station, terminal apparatus, first terminal apparatus, method, program, recording medium and system

ABSTRACT

In order for a first terminal apparatus to transmit a physical uplink control channel to a base station without retuning regardless of a bandwidth part used by the first terminal apparatus, a base station 100 according to the present disclosure includes a communication processing unit 141 configured to communicate with the first terminal apparatus (terminal apparatus 200A) within a bandwidth part of an uplink system band, the bandwidth part being used by the first terminal apparatus (terminal apparatus 200A), wherein the bandwidth part includes a physical uplink control channel region used by the first terminal apparatus (terminal apparatus 200A).

This application is a Continuation of U.S. application Ser. No.17/015,713, filed Sep. 9, 2020, which is a Continuation of U.S.application Ser. No. 16/324,004, filed Feb. 7, 2019, issued as U.S. Pat.No. 10,834,719 on Nov. 10, 2020, which is a National Stage ofInternational Application No. PCT/JP2018/025345, filed Jul. 4, 2018,claiming priority based on JP 2017-149247 filed Aug. 1, 2017, each ofwhich is incorporated herein by reference in its entirety.

BACKGROUND Technical Field

The present disclosure relates to a base station, a terminal apparatus,a first terminal apparatus, a method, a program, a recording medium anda system.

Background Art

In 3rd Generation Partnership Project (3GPP), development ofspecifications of New Radio (NR) which is a fifth generation mobilecommunication system is ongoing. NR is much different from Long TermEvolution (LTE), which is an existing mobile communication system, and,in NR, transmission and reception bandwidths of respective terminalapparatuses may be different (for example, see NPL 1, 2 and 3).

Furthermore, in a general mobile communication system, a terminalapparatus transmits, in uplink, hybrid automatic repeat requestacknowledgement (HARQ-ACK) information indicating whether data receivedin downlink is correctly decoded or not. In NR, a physical uplinkcontrol channel (PUCCH) or a physical uplink shared channel (PUSCH) isused as a physical channel for transmitting uplink control information(UCI) including this HARQ-ACK information.

For example, PLT 1 discloses that a base station determines a PUCCHresource dynamically from among candidates which a terminal apparatus isnotified of in advance and notifies the terminal apparatus of the PUCCHresource.

A PUCCH used in NR is expected to have structure similar to PUCCH format1/1a/1b used in LTE. One of specific common points is support forfrequency hopping in a slot. When frequency hopping is performed intransmission of such a PUCCH, it may be necessary to perform retuning ofa transmission band within an uplink system band because maximumtransmission bandwidths of respective terminal apparatuses may bedifferent in NR for example as described in NPL 1. Specifically, aterminal apparatus whose maximum transmission bandwidth is smaller thanan uplink system bandwidth may need to perform frequency hopping usingboth edges of an uplink system band by performing above describedretuning.

Here, a time period between 50 microseconds and 200 microseconds isneeded for retuning with change of a center frequency, for example asdescribed in NPL 4.

CITATION LIST Patent Literature

-   [PTL 1] JP 2014-504061 T

Non Patent Literature

-   [NPL 1] RAN WG1 “LS on UE RF Bandwidth Adaptation in NR”, 3GPP TSG    RAN WG1 Meeting #87. Reno, USA, 14-18 Nov. 2016. R1-1613663-   [NPL 2] RAN WG1 NR Ad-Hoc #2 “Bandwidth part configuration and    frequency resource allocation”, 3GPP TSG RAN WG1 NR Ad-Hoc #2.    Qingdao, P.R. China 27-30 Jun. 2017. R1-1710164-   [NPL 3] RAN WG1 “Further views on wider bandwidth operations for    NR”, 3GPP TSG RAN WG1 Meeting #89. Hangzhou, P.R. China 15-19    May 2017. R1-1708494-   [NPL 4] RAN WG4 “Reply LS on UE RF Bandwidth Adaptation in NR”, 3GPP    TSG RAN WG1 Meeting #88bis. Spokane, USA, 3-7 Apr. 2017. R1-1704179    (R4-1702029)

SUMMARY Technical Problem

However, in order to perform retuning, insertion of a guard period isneeded, for example. As a result, communication resource usable fortransmission of a PUCCH is decreased, which may cause reduction ofcoverage.

An example object of the present disclosure is to provide a basestation, a terminal apparatus, a first terminal apparatus, a method, aprogram, a recording medium and system enables a first terminalapparatus to transmit a physical uplink control channel to a basestation without retuning regardless of a bandwidth part used by thefirst terminal apparatus.

Solution to Problem

According to one example aspect of the present disclosure, a basestation includes a communication processing unit configured tocommunicate with a first terminal apparatus in an active uplinkbandwidth part of an uplink system band, the active uplink bandwidthpart being used by the first terminal apparatus, wherein the basestation is configured to transmit, to the first terminal apparatus,first control information identifying a relative resource of a physicaluplink control channel within the active uplink bandwidth part, therelative resource being a resource for the first terminal apparatus touse for transmission of the physical uplink control channel.

According to one example aspect of the present disclosure, a terminalapparatus includes a communication processing unit configured tocommunicate with a base station in an active uplink bandwidth part of anuplink system band, wherein the terminal apparatus is configured toreceive, from the base station, first control information identifying arelative resource of a physical uplink control channel within the activeuplink bandwidth part, the relative resource being a resource to use fortransmission of the physical uplink control channel.

According to one example aspect of the present disclosure, a basestation includes a communication processing unit configured tocommunicate with a first terminal apparatus in a bandwidth part of anuplink system band, the bandwidth part being used by the first terminalapparatus, wherein the bandwidth part includes a physical uplink controlchannel region used by the first terminal apparatus.

According to one example aspect of the present disclosure, a firstterminal apparatus includes a communication processing unit configuredto communicate with a base station in a bandwidth part of an uplinksystem band, the bandwidth part being used by the first terminalapparatus, wherein the bandwidth part includes a physical uplink controlchannel region used by the first terminal apparatus.

According to one example aspect of the present disclosure, a firstmethod includes communicating with a first terminal apparatus in abandwidth part of an uplink system band, the bandwidth part being usedby the first terminal apparatus, wherein the bandwidth part includes aphysical uplink control channel region used by the first terminalapparatus.

According to one example aspect of the present disclosure, a secondmethod includes communicating with a base station in a bandwidth part ofan uplink system band, the bandwidth part being used by the firstterminal apparatus, wherein the bandwidth part includes a physicaluplink control channel region used by the first terminal apparatus.

According to one example aspect of the present disclosure, a firstprogram is a program that causes a processor to execute communicatingwith a first terminal apparatus in a bandwidth part of an uplink systemband, the bandwidth part being used by the first terminal apparatus,wherein the bandwidth part includes a physical uplink control channelregion used by the first terminal apparatus.

According to one example aspect of the present disclosure, a secondprogram is a program that causes a processor to execute communicatingwith a base station in a bandwidth part of an uplink system band, thebandwidth part being used by the first terminal apparatus, wherein thebandwidth part includes a physical uplink control channel region used bythe first terminal apparatus.

According to one example aspect of the present disclosure, a firstrecording medium is a non-transitory computer readable recording mediumhaving recorded thereon a program that causes a processor to executecommunicating with a first terminal apparatus in a bandwidth part of anuplink system band, the bandwidth part being used by the first terminalapparatus, wherein the bandwidth part includes a physical uplink controlchannel region used by the first terminal apparatus.

According to one example aspect of the present disclosure, a secondrecording medium is a non-transitory computer readable recording mediumhaving recorded thereon a program that causes a processor to executecommunicating with a base station in a bandwidth part of an uplinksystem band, the bandwidth part being used by the first terminalapparatus, wherein the bandwidth part includes a physical uplink controlchannel region used by the first terminal apparatus.

According to one example aspect of the present disclosure, a systemincludes a base station including a communication processing unitconfigured to communicate with a first terminal apparatus in a bandwidthpart of an uplink system band, the bandwidth part being used by thefirst terminal apparatus, and the first terminal apparatus including acommunication processing unit configured to communicate with the basestation in the bandwidth part, wherein the bandwidth part includes aphysical uplink control channel region used by the first terminalapparatus.

Advantageous Effects of Disclosure

According to an example aspect of the present disclosure, it is possiblefor a first terminal apparatus to transmit a physical uplink controlchannel to a base station without retuning regardless of a bandwidthpart used by the first terminal apparatus. Note that the presentdisclosure may exert other advantageous effects instead of the aboveadvantageous effects or together with the above advantageous effects.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example configuration of Long PUCCHfor the case of one slot including 14 OFDM symbols.

FIG. 2 is a diagram illustrating an example configuration of Long PUCCHfor the case of one slot including 7 OFDM symbols.

FIG. 3 is a diagram illustrating examples of combinations of A shift,cyclic shift number u, and orthogonal cover code number c.

FIG. 4 is a schematic diagram for the case of one terminal apparatustransmitting HARQ-ACK information on a Long PUCCH.

FIG. 5 is a diagram illustrating a specific example of resourcepositions with which frequency hopping is performed respectively byterminal apparatuses A-D whose maximum transmission bandwidths aresmaller than an uplink system bandwidth.

FIG. 6 is an explanatory diagram illustrating an example of a schematicconfiguration of system 1 according to example embodiments of thepresent disclosure.

FIG. 7 is a block diagram illustrating an example of a schematicconfiguration of base station 100 according to a first exampleembodiment.

FIG. 8 is a block diagram illustrating an example of a schematicconfiguration of terminal apparatus 200 according to a first exampleembodiment.

FIG. 9 is a diagram illustrating subbands according to a first specificexample.

FIG. 10 is a diagram illustrating subbands according to a secondspecific example.

FIG. 11 is a diagram illustrating a specific example of two or morecandidate bands set for a terminal group A.

FIG. 12 is a diagram illustrating a specific example of two or morecandidate bands set for a terminal group B.

FIG. 13 is a diagram illustrating positions of Long PUCCHs used by aterminal group A and a terminal group B respectively.

FIG. 14 is a diagram illustrating a specific example of relativeresource number for Long PUCCH resources within a subband or a candidateband.

FIG. 15 is a block diagram illustrating an example of a schematicconfiguration of base station 100 according to a second exampleembodiment.

FIG. 16 is a block diagram illustrating an example of a schematicconfiguration of terminal apparatus 200 according to a second exampleembodiment.

DESCRIPTION OF THE EXAMPLE EMBODIMENTS

Example embodiments of the present disclosure will be described below indetail with reference to the accompanying drawings. Note that, in thepresent description and drawings, elements to which the same or similardescriptions are applicable are denoted by the same reference signs,whereby overlapping descriptions may be omitted.

Description will be given in the following order.

-   -   1. Related Arts    -   2. Overview of Example Embodiments of the Present Disclosure    -   3. Configuration of System    -   4. First Example Embodiment        -   4.1. Configuration of Base Station        -   4.2. Configuration of Terminal Apparatus        -   4.3. Technical Features        -   4.4. Specific Examples    -   5. Second Example Embodiment        -   5.1. Configuration of Base Station        -   5.2. Configuration of Terminal Apparatus        -   5.3. Technical Features    -   6. Other Example Aspects

1. RELATED ARTS

As arts related to example embodiments of the present disclosure, aphysical uplink control channel (PUCCH) used in NR is described mainly.

In NR, there are two types of PUCCHs with different time duration, thatis a PUCCH with a short time duration (hereinafter referred to as “ShortPUCCH”) and a PUCCH with a long time duration (hereinafter referred toas “Long PUCCH”).

A Long PUCCH of them includes 4 to 14 orthogonal frequency divisionmultiplexing (OFDM) symbols. A Long PUCCH is intended to be used mainlyfor coverage improvement.

Furthermore, when the number of bits of UCI transmitted on a Long PUCCHis equal to or less than 2, a Long PUCCH is expected to have a structuresimilar to PUCCH format 1/1a/1b of LTE in light of agreement up to thispoint.

Specific common points are support for frequency hopping in a slot, andbinary phase shift keying (BPSK) or quadrature phase shift keying (QPSK)to be used as a modulation scheme for HARQ-ACK information,multiplication of modulated symbols repeated in a time domain by asequence, and applicability of orthogonal cover code(s) of a time domainto UCI and reference signal(s) (RS(s)).

Note that a slot is one of scheduling units in NR. In case of Normalcyclic prefix (CP), one slot includes 7 or 14 OFDM symbols.

One resource block (RB) includes 12 subcarriers contiguous in afrequency domain. Note that “RB” is used as “a minimum unit of resourceallocation in frequency domain” in present example embodiments because atime period of an RB in NR has not been defined yet. In addition, “RB”as referred to herein may be referred to as “physical resource block(PRB)”.

FIG. 1 is a diagram illustrating example configuration of Long PUCCH forthe case of one slot including 14 OFDM symbols. Specifically, in exampleconfiguration illustrated in FIG. 1 (A), 14 OFDM symbols are used fortransmission of a Long PUCCH. A Long PUCCH with such configuration isrealized when all OFDM symbols in a slot can be used for uplinktransmission.

On the other hand, in example configuration illustrated in FIG. 1 (B),10 OFDM symbols are used for transmission of a Long PUCCH. This is anexample in which slot configuration in time division duplex (TDD) isused. Specifically, after a physical downlink control channels (PDCCHs)are transmitted at the beginning of a slot, a guard period necessary forswitching from downlink to uplink is inserted. Subsequently, a ShortPUCCH and/or a sounding reference signal (SRS) are transmitted at theend of the slot.

A total of 4 OFDM symbols are used for such transmission, and theremaining 10 OFDM symbols are used for transmission of a Long PUCCH.

FIG. 2 is a diagram illustrating an example configuration of Long PUCCHfor the case of one slot including 7 OFDM symbols. In the exampleconfiguration illustrated in FIG. 2 (A), 7 OFDM symbols are used fortransmission of a Long PUCCH. In the example configuration illustratedin FIG. 2 (B), 4 OFDM symbols are used for transmission of a Long PUCCH.

It is possible to multiplex UCI for a plurality of terminal apparatusesin one RB included in a Long PUCCH. This multiplexing is realized withdifferent combinations of a cyclic shift and an orthogonal cover codeused by respective terminals. In the present example embodiments, amultiplexing method for PUCCH format 1/1a/1b of LTE is assumed fordescription.

First, multiplexing by cyclic shifting is realized by using a ConstantAmplitude Zero Auto-Correlation (CAZAC) sequence for transmission of UCIand RSs. A CAZAC sequence has a property of an autocorrelation valuebeing zero in case that a cyclic shift value is not zero. Cyclicshifting represents shift processing which shifts an element at the endof a sequence to the beginning in order. One example of a CAZAC sequenceis a Zadoff-Chu sequence. Furthermore, in LTE, computer generatedsequences (CGS) are used as CAZAC sequences for the case that a sequencelength is 12 or 24.

In case that a one-twelfth of a time period of one OFDM symbol excludinga CP part is expressed by Δ T, it is possible to multiplex a maximum oftwelve UCI and RSs by performing cyclic shifting of u×ΔT (u is aninteger between 0 and 11). Here, in order to maintain orthogonalitybetween terminals, it is necessary that a minimum gap between cyclicshifts is larger than a maximum delay path of a propagation channel. InLTE, a minimum gap between cyclic shifts Δ_(shift)×Δ T is adjusted byusing a parameter common within a cell Δ_(shift) (Δ_(shift)=1, 2, 3).Therefore, the maximum number of multiplexing by cyclic shifting is12/Δ_(shift).

Multiplexing by orthogonal cover codes is realized by performingblock-spreading of UCI and RSs over a plurality of OFDM symbols. Usingorthogonal cover codes enables multiplexing of the same number ofcomplex symbols as its sequence length by block-spreading. Here,orthogonal cover codes are applied independently to respective UCI andRSs before and after frequency hopping, and its sequence length is equalto the number of OFDM symbols allocated to each. As a result, a maximummultiplexing number is a minimum value of the number of OFDM symbolsallocated to respective UCI and RSs before and after frequency hopping.

The maximum number of multiplexing by orthogonal cover codes is 3 incase of the example configuration illustrated in FIG. 1 (A) and is 2 incase of the example configuration illustrated in FIG. 1 (B). On theother hand, in the example configurations illustrated respectively inFIG. 2 (A) and FIG. 2 (B), multiplexing by orthogonal cover codes is notperformed because an RS includes a single OFDM symbol after frequencyhopping.

The number of multiplexed UCI per one RB of Long PUCCH, denoted as N, isexpressed by a product of a maximum multiplexing number by cyclicshifting and a maximum multiplexing number by orthogonal cover codes.For example, when a maximum multiplexing number by cyclic shifting is 4(i.e. Δ_(shift)=3) and a maximum multiplexing number by orthogonal covercodes is 3, 4×3=12 pieces of UCI can be multiplexed per one RB.

FIG. 3 is a diagram illustrating examples of combinations of Δ shift,cyclic shift number u, and orthogonal cover code number c. It ispossible to perform numbering of resources which can be multiplexed perone RB of Long PUCCH by selecting one of the combinations as illustratedin FIG. 3. Note that FIG. 3 is one example, and for example differentnumbering per cell is possible.

FIG. 4 is a schematic diagram for the case of one terminal apparatustransmitting HARQ-ACK information on a Long PUCCH. A base stationtransmits data for a terminal apparatus on a physical downlink sharedchannel (PDSCH), and transmits downlink control information (DCI)including allocation information for the data on a physical downlinkcontrol channel (PDCCH). On the other hand, the terminal apparatusreceives the data on the PDSCH based on the DCI after receiving the DCIfor the terminal apparatus on the PDCCH. Then, the terminal apparatustransmits, on a Long PUCCH in an uplink slot, HARQ-ACK informationindicating whether the data is correctly decoded or not.

In NR, for a terminal apparatus, bandwidth part(s) including contiguousRBs is set for uplink and downlink respectively. Note that the number ofRBs set for a bandwidth part is equal to or less than a maximumbandwidth supported by respective terminal apparatuses. One or morebandwidth parts are set for respective terminals. A terminal apparatusreceives downlink signals within an active downlink bandwidth part ofthe set bandwidth part(s), and transmits uplink signals using an activeuplink bandwidth part of the set bandwidth part(s).

2. OVERVIEW OF EXAMPLE EMBODIMENTS OF THE PRESENT DISCLOSURE

First, an overview of example embodiments of the present disclosure isdescribed.

(1) Technical Problem

As maximum transmission bandwidths of respective terminal apparatusesmay be different in NR as described above, a hopping gap in frequencydomain may differ from terminal apparatus to terminal apparatus whenfrequency hopping is performed in transmission of a Long PUCCH. Forexample, a terminal apparatus whose maximum transmission bandwidth issmaller than an uplink system bandwidth may perform frequency hopping toa region other than edges of an uplink system band for transmission of aLong PUCCH.

FIG. 5 is a diagram illustrating a specific example of resourcepositions with which frequency hopping is performed respectively byterminal apparatuses A-D whose maximum transmission bandwidths aresmaller than an uplink system bandwidth. As described in FIG. 5,fragmented resources may exist. Existence of such fragmented resourcesmay cause flexibility of PUSCH resource allocation to be decreased.

In addition, it is agreed in NR to use both of Cyclic Prefix-OrthogonalFrequency Division Multiplexing (CP-OFDM) and Discrete FourierTransform-spread-Orthogonal Frequency Division Multiplexing (DFT-s-OFDM)as an uplink transmission waveform. Furthermore, only contiguous RBallocation is assumed to be supported when DFT-s-OFDM is used as atransmission waveform of PUSCH.

Here, in case of DFT-s-OFDM, the number of contiguous RBs which can beallocated to one terminal apparatus is limited in light of existence offragmented RBs illustrated in the above described FIG. 5. In addition,in case of CP-OFDM, although allocation of non-contiguous RBs ispossible, resource allocation which utilizes all fragmented RBs isdifficult in light of overhead of resource allocation information.Therefore, there may be a possibility that the number of unused RBsincreases and use efficiency of radio resources is decreased.

As a method to prevent occurrence of the above described fragmentedresources, it is proposed, for example as disclosed in the followingreference document, that a PUCCH is transmitted on a resource whichexists at the edge of a subband by setting a plurality of subbands in anuplink system band.

-   [reference document] CMCC “Discussion on subband-based PUCCH    resource allocation and indication”, 3GPP TSG RAN WG1 Meeting NR    Ad-Hoc #2. Qingdao, China, 27-30 Jun. 2017. R1-1710782

However, in the above reference document, there is no disclosure ofsetting a limitation on the number of RBs and a start position infrequency domain for a subband. Therefore, overhead for notifying aterminal apparatus of information on a subband will be high if a subbandwith any number of RBs can be located at any position in frequencydomain.

Here, a terminal apparatus whose maximum transmission bandwidth issmaller than an uplink system bandwidth can perform frequency hoppingusing both edges of an uplink system band by performing retuning whichswitches transmission bands within an uplink system band. However, atime period between 50 microseconds and 200 microseconds for examplewould be necessary for retuning which is accompanied by a change of acenter frequency. In order to perform such retuning, for example,insertion of a guard period would be necessary, and the number of OFDMsymbols available for transmission of a Long PUCCH would decrease, whichmay cause a reduction of coverage.

(2) Technical Features

According to example embodiments of the present disclosure, for example,a base station includes a communication processing unit configured tocommunicate with a first terminal apparatus in a bandwidth part of anuplink system band, the bandwidth part being used by the first terminalapparatus, wherein the bandwidth part includes a physical uplink controlchannel region used by the first terminal apparatus.

Furthermore, according to example embodiments of the present disclosure,for example, a first terminal apparatus includes a communicationprocessing unit configured to communicate with a base station in abandwidth part of an uplink system band, the bandwidth part being usedby the first terminal apparatus, wherein the bandwidth part includes aphysical uplink control channel region used by the first terminalapparatus.

According to the example embodiments, for example, it is possible for afirst terminal apparatus to transmit a physical uplink control channelto a base station without retuning regardless of a bandwidth part usedby the first terminal apparatus. More specifically, it is possible for afirst terminal apparatus to transmit a physical uplink control channelto a base station without retuning even if the bandwidth part of thefirst terminal apparatus is smaller than an uplink system band.

Note that, the above described technical feature is one specific exampleof example embodiments of the present disclosure, and of course theexample embodiments of the present disclosure are not limited to theabove described technical features.

3. CONFIGURATION OF SYSTEM

With reference to FIG. 6, an example of a schematic configuration of asystem 1 according to the example embodiments of the present disclosureis described. FIG. 6 is an explanatory diagram illustrating an exampleof a schematic configuration of the system 1 according to the exampleembodiments of the present disclosure. According to FIG. 6, the system 1includes a base station 100, a terminal apparatus 200A and terminalapparatus 200B. Each of terminal apparatus 200A and terminal apparatus200B is generally referred to as a terminal apparatus 200 below.

For example, the system 1 is a system conforming to Third GenerationPartnership Project (3GPP) standards. More specifically, for example,the system 1 may be a system conforming to standards/specifications ofLTE/LTE-Advanced/LTE-Advanced Pro and/or System Architecture Evolution(SAE). Alternatively, the system 1 may be a system conforming tostandards/specifications of 5G/New Radio (NR). It is understandable thatthe system 1 is not limited to these examples.

(1) Base Station 100

The base station 100 is a node of a radio access network (RAN) andperforms wireless communication with terminal apparatuses located in acoverage area (e.g. terminal apparatus 200A and terminal apparatus200B).

For example, the base station 100 may be an evolved Node B (eNB), ageneration Node B (gNB) in 5G, or a transmission reception point (TRP).The base station 100 may include a plurality of units (or a plurality ofnodes). The plurality of units (or plurality of nodes) may include afirst unit (or a first node) performing processing of a higher protocollayer, and a second unit (or a second node) performing processing of alower protocol layer. As an example, the first unit may be referred toas a center/central unit (CU), and the second unit may be referred to asa distributed unit (DU) or an access unit (AU). As another example, thefirst unit may be referred to as a digital unit (DU), and the secondunit may be referred to as a radio unit (RU) or a remote unit (RU). Thedigital unit (DU) may be a base band unit (BBU), and the RU may be aremote radio head (RRH) or a remote radio unit (RRU). Terms used torefer to the first unit (or first node) and the second unit (or secondnode) are, of course, not limited to these examples. Alternatively, thebase station 100 may be a single unit (or single node). In this case,the base station 100 may be one of the multiple units (e.g., one of thefirst unit and the second unit) and may be connected to another one ofthe multiple units (e.g., the other one of the first unit and the secondunit).

(2) Terminal Apparatus 200

The terminal apparatus 200 performs wireless communication with a basestation. For example, when the terminal apparatus 200 is located in acoverage area of the base station 100, the terminal apparatus 200performs wireless communication with the base station 100. For example,the terminal apparatus 200 is a user equipment (UE). The terminalapparatus 200 may be referred to as “a wireless communicationapparatus”, “a wireless communication terminal”, “a user equipment”, “auser terminal” or “a mobile station”, etc., instead of “a terminalapparatus”.

In the present example embodiments, for example, the terminal apparatus200A has a different maximum reception bandwidth and a different maximumtransmission bandwidth from the terminal apparatus 200B. Morespecifically, the terminal apparatus 200A has a smaller maximumreception bandwidth and a smaller maximum transmission bandwidth thanthe terminal apparatus 200B. As described, in the system 1, terminalapparatuses with different maximum reception bandwidths/maximumtransmission bandwidths coexist.

4. FIRST EXAMPLE EMBODIMENT

The first example embodiment of the present disclosure is described withreference to FIG. 7 to FIG. 14.

4.1. Configuration of Base Station

With reference to FIG. 7, an example of a configuration of a basestation 100 according to the first example embodiment is described. FIG.7 is a block diagram illustrating an example of a schematicconfiguration of the base station 100 according to the first exampleembodiment. According to FIG. 7, the base station 100 includes awireless communication unit 110, a network communication unit 120, astorage unit 130, and a processing unit 140.

(1) Wireless Communication Unit 110

The wireless communication unit 110 transmits and receives signalswirelessly. For example, the wireless communication unit 110 receives asignal from a terminal apparatus and transmits a signal to a terminalapparatus.

(2) Network Communication Unit 120

The network communication unit 120 receives a signal from a network andtransmits a signal to a network.

(3) Storage Unit 130

The storage unit 130 temporarily or permanently stores programs(instructions) and parameters for operations of the base station 100 aswell as various data. The program includes one or more instructions foroperations of the base station 100.

(4) Processing Unit 140

The processing unit 140 provides various functions of the base station100. The processing unit 140 includes a communication processing unit141 and an information obtaining unit 143. Note that the processing unit140 may further include a constituent component other than theseconstituent components. In other words, the processing unit 140 may alsoperform operations other than the operations of these constituentelements. Concrete operations of the communication processing unit 141and the information obtaining unit 143 will be described later indetail.

For example, the processing unit 140 (the communication processing unit141) communicates with a terminal apparatus (e.g., the terminalapparatus 200) via the wireless communication unit 110.

(5) Example Implementation

The wireless communication unit 110 may be implemented by an antenna, aradio frequency (RF) circuit, and the like, and the antenna may be adirectional antenna. The network communication unit 120 may beimplemented by a network adapter and/or a network interface card, andthe like. The storage unit 130 may be implemented a memory (e.g., anonvolatile memory and/or volatile memory) and/or a hard disk, and thelike. The processing unit 140 may be implemented by one or moreprocessors such as a baseband (BB) processor and/or other types ofprocessors, and the like. The communication processing unit 141 and theinformation obtaining unit 143 may be implemented by the same processor,or may be implanted separately by different processors. The memory (thestorage unit 130) may be included in the one or more processors, or maybe outside of the one or more processors.

The base station 100 may include a memory storing a program(instructions), and one or more processors capable of executing theprogram (the instructions). The one or more processors may execute theprogram to perform the operations of the processing unit 140 (operationsof the communication processing unit 141 and/or the informationprocessing unit 143). The program may be a program that causes aprocessor to execute the operations of the processing unit 140(operations of the communication processing unit 141 and/or theinformation processing unit 143).

Note that the base station 100 may be virtualized. In other words, thebase station 100 may be implemented as a virtualized machine. In thiscase, the base station 100 (the virtualized machine) may operate as avirtual machine on a physical machine (hardware) including a processorand a memory and a hypervisor.

4.2. Configuration of Terminal Apparatus

With reference to FIG. 8, an example of a configuration of a terminalapparatus 200 according to the first example embodiment is described.FIG. 8 is a block diagram illustrating an example of a schematicconfiguration of the terminal apparatus 200 according to the firstexample embodiment. According to FIG. 8, the terminal apparatus 200includes a wireless communication unit 210, a storage unit 220, and aprocessing unit 230.

(1) Wireless Communication Unit 210

The wireless communication unit 210 transmits and receives signalswirelessly. For example, the wireless communication unit 210 receives asignal from a base station and transmits a signal to a base station.

(2) Storage Unit 220

The storage unit 220 temporarily or permanently stores programs(instructions) and parameters for operations of the terminal apparatus200 as well as various data. The program includes one or moreinstructions for operations of terminal apparatus 200.

(3) Processing Unit 230

The processing unit 230 provides various functions of the terminalapparatus 200. The processing unit 230 includes a communicationprocessing unit 231. Note that the processing unit 230 may furtherinclude constituent components other than these constituent components.In other words, the processing unit 230 may also perform operationsother than the operations of these constituent elements. Concreteoperations of the communication processing unit 231 will be describedlater in detail.

For example, the processing unit 230 (the communication processing unit231) communicates with a base station (e.g., the base station 100) viathe wireless communication unit 210.

(4) Example Implementation

The wireless communication unit 210 may be implemented by an antenna, aradio frequency (RF) circuit, and the like. The storage unit 220 may beimplemented by a memory (e.g., a nonvolatile memory and/or volatilememory) and/or a hard disk, and the like. The processing unit 230 may beimplemented by one or more processors such as a baseband (BB) processorand/or other types of processors, and the like. The communicationprocessing unit 231 may be implemented by the same processor, or may beimplanted separately by different processors. The memory (the storageunit 220) may be included in the one or more processors, or may beoutside of the one or more processors. As one example, the processingunit 230 may be implemented in a system on chip (SoC).

The terminal apparatus 200 may include a memory storing a program(instructions), and one or more processors capable of executing theprogram (the instructions). The one or more processors may execute theprogram to perform operations of the processing unit 230 (operations ofthe communication processing unit 231). The program may be a programthat causes a processor to execute the operations of the processing unit230 (operations of the communication processing unit 231).

4.3. Technical Features

Next, technical features of the first example embodiment are described.

The base station 100 (the communication processing unit 141)communicates with a first terminal apparatus (the terminal apparatus200A) in a bandwidth part of an uplink system band, the bandwidth partbeing used by the first terminal apparatus (the terminal apparatus200A). The first terminal apparatus (the communication processing unit231 of the terminal apparatus 200A) communicates with the base station100 in the bandwidth part. The bandwidth part includes a physical uplinkcontrol channel region used by the first terminal apparatus (theterminal apparatus 200A).

According to such configuration, for example, it is possible for thefirst terminal apparatus (the terminal apparatus 200A) to transmit aphysical uplink control channel to the base station 100 without retuningregardless of the bandwidth part used by the first terminal apparatus(the terminal apparatus 200A). More specifically, it is possible for thefirst terminal apparatus (terminal apparatus 200A) to transmit aphysical uplink control channel to the base station 100 without retuningeven if the bandwidth part of the first terminal apparatus (the terminalapparatus 200A) is smaller than the uplink system band.

(1) Bandwidth Part

The bandwidth part may include a plurality of physical uplink controlchannel regions used by the first terminal apparatus (the terminalapparatus 200A). Here, each of the plurality of physical uplink controlchannel regions may be separated from each other in frequency direction.

For example, when frequency hopping is performed for transmission of aphysical uplink control channel, one of the plurality of physical uplinkcontrol channel regions may be a region for transmitting a physicaluplink control channel before frequency hopping, and another one of theother physical uplink control channels may be a region for transmittinga physical uplink control channel after frequency hopping.

In addition, the uplink system band includes a plurality of subbands,and each of the plurality of subbands includes a plurality of resourceblocks contiguous in frequency direction. In the uplink system band withsuch configuration, the bandwidth part includes one or more of theplurality of subbands.

In addition, the bandwidth part may be one or more of the plurality ofsubbands. That is, a size and a position of the bandwidth part may bedetermined by one or more subbands.

Furthermore, the bandwidth part may be configured to correspond to aspecific numerology. The specific numerology may be a parameter based onat least any one of subcarrier spacing, a transmission time interval(TTI), and a cyclic prefix (CP) type. In addition, one or more bandwidthparts may be set semi-statically for a terminal apparatus per componentcarrier (CC).

Note that when a plurality of bandwidth parts are set for one terminalapparatus, different numerologies may be set for the plurality ofbandwidth parts respectively. Different numerologies may be set asscalable values, for example, by setting a basic subcarrier spacing f₀to be 15 kHz and other subcarrier spacing to be f_(sc)=2^(n)×f₀, etc.That is, subcarrier spacing may be a scalable value of a power of 2. Inaddition, a different CP type may be set for each of the plurality ofbandwidth parts. That is, any one of Normal CP and Extended CP may beset for each bandwidth part.

Furthermore, the bandwidth part used by the first terminal apparatus(the terminal apparatus 200A) may include one or more of subbandsincluded in a bandwidth part used by a second terminal apparatus(terminal apparatus 200B) different from the first terminal apparatus(the terminal apparatus 200A).

Example configuration of specific subbands will be described later.

(2) Physical Uplink Control Channel Region

The physical uplink channel region is located within a subband includedin the bandwidth part.

For example, when the bandwidth part includes two or more subbands, thephysical uplink control channel region is located within one subband outof the two or more subbands included in the bandwidth part.

Note that, the physical uplink control channel region may be locatedwithin a subband at the edge of the two or more subbands. Here, thesubband at the edge is a subband which is the lowest in frequencydirection out of the two or more subbands, or a subband which is thehighest in frequency direction out of the two or more subbands.

Here, when the bandwidth part includes a plurality of physical uplinkcontrol channel regions separated from each other in frequency directionas described above, respective physical uplink control channel regionsare for example a first physical uplink control channel region and asecond physical uplink control channel region. In this case, as oneexample, the first physical uplink control channel region and the secondphysical uplink control channel region are located within differentsubbands. That is, the first physical uplink control channel region islocated within one subband out of the two or more subbands included inthe bandwidth part, and the second physical uplink control channelregion is located within one subband out of the two or more subbandsincluded in the bandwidth part, the one subband being different from asubband within which the first physical uplink control channel region islocated. Note that the first physical uplink control channel region andthe second physical uplink control channel region are not limited to theabove case, and may be included at positions separated from each otherin frequency direction within the same subband.

Furthermore, the physical uplink control channel region is located in apredetermined portion within the subband. Here, the predeterminedportion is a portion at the edge of the subband, or a portion spacedfrom the edge of the subband with a predetermined gap. For example, thephysical uplink control channel region may be located between the edgeof the subband and a portion spaced from the edge by 20%, 25% and/or 50%of a bandwidth of the subband.

Candidate Band

The physical uplink control channel region may be located within onecandidate band out of two or more candidate bands in the bandwidth part.Each of the two or more candidate bands is one subband within thebandwidth part, or two or more subbands contiguous in frequencydirection within the bandwidth part.

For example, specific positions of the first and the second physicaluplink control channel region are as follows. For example, when acandidate band within which the physical uplink control channel regionis located includes one subband, the first physical uplink controlchannel region is located at an edge of the subband, and the secondphysical uplink control channel region is located at another edge of thesubband. On the other hand, when a candidate band within which thephysical uplink control channel region is located includes two or moresubbands contiguous in frequency direction, the first physical uplinkcontrol channel region is located within a subband located at an edge ofthe candidate band, and the second physical uplink control channelregion is located within a subband located at another edge of thecandidate band.

(3) Control Information

The base station 100 (the information obtaining unit 143) obtains firstcontrol information for specifying the physical uplink control channelregion, and the base station 100 (the communication processing unit 141)transmits the first control information to the first terminal apparatus(the terminal apparatus 200A).

When the physical uplink control channel region is located within asubband included in the bandwidth part as described above, controlinformation for specifying a subband within which the physical uplinkcontrol channel region is located is used as the first controlinformation.

On the other hand, when the physical uplink control channel region islocated within one candidate band out or the two or more candidate bandswithin the bandwidth part as described above, control information foridentifying a candidate band within which the physical uplink controlchannel region is located is used as the first control information.

Specifically, for example, the following two types of indexes are usedas the first control information. First, one index is an index (referredto as an absolute index below) for identifying a candidate band withinwhich the physical uplink control channel region is located out of aplurality of candidate bands within the uplink system band. Anotherindex is an index (referred to as a relative index below) foridentifying a candidate band within which the physical uplink controlchannel region is located out of the two or more candidate bands withinthe bandwidth part.

For example, when there is an agreement, between a base station and aterminal apparatus, that a physical uplink control channel region islocated within a subband located at the edge of a candidate band, it ispossible for the first terminal apparatus (the terminal apparatus 200A)to specify a subband within which the physical uplink control channelregion is located by identifying a candidate band based on the index.

In addition, for example, the base station 100 (the communicationprocessing unit 141) may transmit downlink control information (DCI)including the index to the first terminal apparatus (the terminalapparatus 200A). The base station 100 (the communication processing unit141) may transmit a media access control (MAC) control element includingthe index to the first terminal apparatus (the terminal apparatus 200A).

When a candidate band within which the physical uplink control channelregion is located is identified by the first control information asdescribed above, the base station 100 (the information obtaining unit143) may obtain second control information for specifying the two ormore candidate bands. Then, the base station 100 (the communicationprocessing unit 141) may transmit the second control information to thefirst terminal apparatus (the terminal apparatus 200A).

Specifically, the base station 100 (the communication processing unit141) transmits a MAC control element including the second controlinformation to the first terminal apparatus (the terminal apparatus200A). Note that the base station 100 (the communication processing unit141) may transmit a radio resource control (RRC) message including thesecond control information to the first terminal apparatus (the terminalapparatus 200A).

4.4. Specific Examples

Next, specific examples of processing performed in the system 1 isdescribed.

(1) Specific Examples of Subbands First Specific Example

FIG. 9 is a diagram illustrating subbands according to a first specificexample. In the first specific example, as described in FIG. 9, subbandsare set by dividing an uplink system band equally by the number ofsubbands, N_(sb). Note that, if the number of RBs of an uplink systemband, N^(UL) _(RB) is indivisible by N_(sb), a difference betweennumbers of RBs of subbands can be equal to or less than 1 by thefollowing formula as one example:

$\begin{matrix}{{P = {N_{RB}^{UL} - {N_{sb}\lfloor {N_{RB}^{UL}/N_{sb}} \rfloor}}}{{N_{RB}^{sb}(n)} = \{ {\begin{matrix}\lceil {N_{RB}^{UL}/N_{sb}} \rceil \\\lfloor {N_{RB}^{UL}/N_{sb}} \rfloor\end{matrix}\mspace{20mu}\begin{matrix}{{{if}\mspace{14mu} n} < P} \\{otherswise}\end{matrix}} }} & \lbrack {{Math}.\mspace{14mu} 1} \rbrack\end{matrix}$wherein N^(sb) _(RB)(n) represents the number of RBs of n-th subband.

As one example, when the number of RBs of an uplink system band, N^(UL)_(RB) is 275 and the number of subbands, N_(sb) is 10, P=5 according tothe above formula. That is, each of 0th to 4th subbands includes 28 RBs,and each of 5th to 9th subbands includes 27 RBs.

In addition, the number of RBs per subband, N_(RB) may be assigned.Here, when the number of RBs of an uplink system band, N^(UL)RB isindivisible by N_(RB), the number of RBs of a subband located at any oneedge of an uplink system band may be N^(UL) _(RB) mod N_(RB) as oneexample.

Second Specific Example

FIG. 10 is a diagram illustrating subbands according to a secondspecific example. In the second specific example, a reserved region isset as shown in FIG. 10.

Here, the reserved region is a region for securing a static Long PUCCHresource per terminal apparatus. Specifically, for example, the reservedregion is used as a Long PUCCH resource for a terminal apparatus totransmit, to a base station, any requests, e.g. a scheduling request(SR) and Beam Failure recovery request, and as a Long PUCCH resourcesfor transmitting periodic channel state information (CSI). It ispreferable to use RBs at both edges of an uplink system band as such aLong PUCCH resource of a reserved region. This is for avoiding reductionof the number of contiguous RBs which can be allocated dynamically, dueto separation of an uplink system band by statically allocatedresources.

Therefore, in the second specific example, a total of N^(rsv) _(RB) RBsat both edges of an uplink system band is a reserved region as shown inFIG. 9. In addition, in the second specific example, the number of RBsexcluding N^(rsv) _(RB) RBs from an uplink system band, N′^(UL) _(RB) isdivided equally by the number of subbands, N_(sb). Note that, if N′^(UL)_(RB) is indivisible by N_(sb), a difference between numbers of RBs ofsubbands can be equal to or less than 1 by the following formula as oneexample:

$\begin{matrix}{N_{RB}^{\prime\;{UL}} = {N_{RB}^{UL} - N_{RB}^{rsv} - ( {N_{RB}^{rsv}\;{mod}\; 2} )}} & \lbrack {{Math}.\mspace{14mu} 2} \rbrack \\{P^{\prime} = {N_{RB}^{\prime\;{UL}} - {N_{sb}\lfloor {N_{RB}^{\prime\;{UL}}/N_{sb}} \rfloor}}} & \; \\{{N_{RB}^{\prime\;{sb}}(n)} = \{ {\begin{matrix}\lceil {N_{RB}^{\prime\;{UL}}/N_{sb}} \rceil \\\lfloor {N_{RB}^{\prime\;{UL}}/N_{sb}} \rfloor\end{matrix}\mspace{25mu}\begin{matrix}{{{if}\mspace{14mu} n} < P^{\prime}} \\{otherswise}\end{matrix}} } & \;\end{matrix}$wherein N″^(sb) _(RB)(n) represents the number of RBs of n-th subband.

As one example, the number of RBs of an uplink system band, N^(UL)RB is275, the number of subbands, N_(sb) is 10, and a total of 8 RBsincluding 4 RBs from each band edge is a reserved region. In this case,according to the above formula, P′=7. That is, each of 0th to 6thsubbands includes 27 RBs, and each of 7th to 9th subbands includes 26RBs.

In addition, the number of RBs per subband, N_(RB) may be assigned.Here, when the number of RBs excluding N^(rsv) _(RB) RBs from an uplinksystem band, N′^(UL) _(RB) is indivisible by N_(RB), the number of RBsof a subband located at any one edge out of a band obtained by excludingN^(rsv) _(RB) RBs from an uplink system band may be N′^(UL) _(RB) modN_(RB) as one example.

Notification of Configuration of Subbands

The number of subbands N_(sb) or the number of RBs per subband N_(RB)may be transmitted per cell, per terminal apparatus, or per group towhich terminal apparatuses belongs. In addition, the number of subbandsN_(sb) or the number of RBs per subband N_(RB) may be included inRemaining Minimum System Information (RMSI), and/or may be included inan RRC message.

In addition, when an increase of overhead is allowed, a position of astart RB and the number of contiguous RBs per subband may be set.

(2) Specific Example of Candidate Band

The base station 100, for example, sets the two or more candidate bandsout of two or more subbands included in the bandwidth part when the basestation 100 sets the bandwidth part for the first terminal apparatus(the terminal apparatus 200A). Then, when the bandwidth part set for thefirst terminal apparatus (the terminal apparatus 200A) becomes active,the base station 100 identifies one candidate band out of the two ormore candidate bands, and notifies the first terminal apparatus (theterminal apparatus 200A) of information indicating the identifiedcandidate band as the first control information. Then the first terminalapparatus (the terminal apparatus 200A) transmits a Long PUCCH using RBswithin subbands located at both edges of a candidate band which thefirst terminal apparatus is notified of by the base station 100.

For example, the candidate band is uniquely identified by a combinationof a start position of subbands SB_(start), and the number of contiguoussubbands L_(CSBs). A set value X uniquely specifying this combinationcan be calculated by the following formula:if (L _(CSBs)−1)≤└N _(sb)/2┘ thenX=N _(sb)(L _(CSBs)−1)+SB_(start)elseX=N _(sb)(N _(sb) −L _(CSBs)+1)+(N _(sb)−1−SB_(start))  [Math. 3]wherein the number of bits of the set value X is as follows:┌log₂(N _(sb)(N _(sb)+1)/2)┐  [Math. 4]

Note that the base station 100 may not set a candidate band, and maydirectly notify the first terminal apparatus (the terminal apparatus200A) of the set value X using a MAC control element and/or DCI. Forsuch a notification way, for example, when the number of subbands N_(sb)is 10, 6 bits would be needed for transmission of the set value X. Inparticular, in case of notification of the set value X using DCI, the 6bits is high overhead.

Therefore, the base station 100 notifies, in advance, the first terminalapparatus (the terminal apparatus 200A) of the second controlinformation for specifying the two or more candidate bands. Then, thebase station 100 transmits, to the first terminal apparatus (theterminal apparatus 200A), only the index (the first control information)for identifying one candidate band out of the two or more candidatebands, using a MAC CE and/or DCI. This makes it possible to reduce thenumber of bits for identifying a candidate band within which thephysical uplink control channel region is located.

Next, candidate bands set for two types of terminal groups whosebandwidth parts are different is described. First, a bandwidth partwhich has the same bandwidth as an uplink system band is set for aterminal group A, and a bandwidth part which has a smaller bandwidththan the uplink system band is set for a terminal group B. As oneexample, if uplink system bandwidth is 50 MHz, the terminal group Aincludes a plurality of terminal apparatuses whose maximum transmissionbandwidths are 50 MHz, and the terminal group B includes a plurality ofterminal apparatuses whose maximum transmission bandwidths are 25 MHz.For example, the first terminal apparatus (the terminal apparatus 200A)is included in the terminal group B, and the second terminal apparatus(the terminal apparatus 200B) is included in the terminal group A. Notethat, the terminal group B may include a terminal apparatus whosemaximum transmission bandwidth is 50 MHz as a bandwidth of a bandwidthpart is equal to or smaller than a maximum transmission bandwidth of aterminal apparatus.

FIG. 11 is a diagram illustrating a specific example of two or morecandidate bands set for terminal group A. When 8 candidate bands are setfor the terminal group A as shown in FIG. 11, a set value table offollowing Table 1 is given and transmitted as the second controlinformation. For example, an RRC message and/or a MAC CE can be used asa notification method of the set value table.

TABLE 1 Index of Start Number of Candidate Position of Contiguous SetBand, Subbands, Subbands, Value, m SB_(start) L_(CSBs) X 0 0 1 0 1 9 1 92 0 3 20 3 7 3 27 4 1 4 31 5 5 4 35 6 3 4 33 7 0 10 19

The base station 100 notifies the terminal group A of index m of acandidate band, within which the physical uplink control channel regionis located, out of these candidate bands using a MAC CE and/or DCI. Asthe number of bits necessary for this notification is 3, the number ofbits can be reduced as compared to the case of direct notification ofthe set value X using 6 bits as described above.

FIG. 12 is a diagram illustrating a specific example of two or morecandidate bands set for a terminal group B. As shown in FIG. 12, whenfour candidate bands are set for the terminal group B, a set value X canbe assigned by the absolute index or the relative index, for example.

In the specific example shown in FIG. 12, for example, the absoluteindex can identify each of candidate bands based on absolute subbandnumbers uniquely identifying respective subbands #0-#9 included in anuplink system band. In addition, for example, the relative index canidentify each of candidate bands based on relative subband numbersuniquely identifying respective subbands (#0)-(#3) included in abandwidth part.

When the absolute index is used, a set value table of following Table 2is given and transmitted as the second control information. Here, “StartPosition of Subbands, SB_(start)” represents a start position based onthe absolute subband numbers. For example, an RRC message and/or a MACCE can be used as a notification method of the set value table.

TABLE 2 Index of Start Number of Candidate Position of Contiguous SetBand, Subbands, Subbands, Value, m SB_(start) L_(CSBs) X 0 3 1 3 1 6 1 62 4 2 14 3 3 4 33

When the relative index is used, a set value table of following Table 3is given and transmitted as the second control information. Here, “StartPosition of Subbands, SB_(start)” represents a start position based onthe relative subband numbers. For example, an RRC message and/or a MACCE can be used as a notification method of the set value table.

TABLE 3 Index of Start Number of Candidate Position of Contiguous SetBand, Subbands, Subbands, Value, m SB_(start) L_(CSBs) X 0 0 1 0 1 3 1 32 1 2 5 3 0 4 7

As apparent from Table 2 and Table 3, the number of bits necessary fornotification of a set value table is 6×4=24 in case of using theabsolute index, and is 4×4=16 in case of using the relative index.Therefore, when the number of bits is variable, the number of bits canbe reduced by using the relative index. On the other hand, when theabsolute index is used, there is an advantage that setting of abandwidth part and notification of a set value table can be performedindependently.

Example of Notification of Candidate Band within which Physical UplinkControl Channel Region is Located

After the terminal group A and the terminal group B are respectivelyinformed of the set value table, the base station 100 notifies aterminal apparatus of an index m of a candidate band used fortransmission of HARQ-ACK information, that is an index m of a candidateband within which a physical uplink control channel is located.

As a notification method of this index m, DCI for scheduling a PDSCHcorresponding to the HARQ-ACK information may be used. This enablesdynamic notification of index m per transmission of a PDSCH, i.e. pertransmission of HARQ-ACK information, and enables flexible uplinkscheduling.

In addition, a system may be set such that the index m is switcheddynamically per number of subframes corresponding to a repetition numberwhen the DCI includes the repetition number. Furthermore, the DCI mayinclude control information indicating that the index m is switcheddynamically per number of subframes corresponding to a repetitionnumber. Note that the index m may be different between subframestransmitted repeatedly and control information indicating this may beincluded in the DCI.

Note that the index m may be transmitted using an RRC message and/or aMAC CE when dynamic control is not needed.

FIG. 13 is a diagram illustrating positions of Long PUCCHs used by aterminal group A and a terminal group B respectively. In examplenotification shown in FIG. 13, it is assumed that the terminal group Ais notified of indexes m=2, 3, 6, and the terminal group B is notifiedof an index m=3. Portions other than Long PUCCHs can be used ascontiguous bands which can be allocated for PUSCH transmissionrespectively in a band in which subband numbers (absolute subbandnumbers in an example of FIG. 13) are from #0 to #2, a band in whichsubband numbers are from #3 to #6, and a band in which subband numbersare from #7 to #9.

As described above, although the terminal group A and the terminal groupB have different active bandwidth parts from each other, it is possibleto concentrate and allocate all Long PUCCHs near borders of commonsubbands by using physical uplink control channel regions located withinthe common subbands. This makes it possible to multiplex Long PUCCHsefficiently and suppress fragmentation of radio resources.

Example Placement of Physical Uplink Control Channels within Subband orCandidate Band

A terminal apparatus needs to specify a relative resource number for aLong PUCCH resource within a subband or a candidate band as well as thesubband or the candidate band within which a physical uplink controlchannel region for transmitting HARQ-ACK information is located. By thisrelative resource number, a relative RB number within the subband or thecandidate band and a resource number within an RB may be specified. Theresource number within the RB may specify a cyclic shift number and/oran orthogonal cover code number to be applied to a Long PUCCH.

Note that, when frequency hopping is performed, this relative resourcenumber may specify at least any one of a relative position of a physicaluplink control channel region within a subband or a candidate bandbefore frequency hopping, and a relative position of a physical uplinkcontrol channel region within a subband or a candidate band afterfrequency hopping.

FIG. 14 is a diagram illustrating a specific example of relativeresource number for Long PUCCH resources within a subband or a candidateband.

This relative resource number may be determined implicitly based oninformation on a resource in which a PDSCH corresponding to HARQ-ACKinformation is transmitted. An example of this information is a firstOFDM symbol number, a first RB number, a last OFDM symbol number or alast RB number with which the PDSCH is scheduled, or a combination ofany of them.

In addition, the relative resource number may be determined implicitlybased on information on a PDCCH resource in which DCI for scheduling aPDSCH is transmitted. An example of this information is a first OFDMsymbol number, a first RB number, a last OFDM symbol number, a last RBnumber, a first or last index of a resource element group (REG), or afirst or last index of control channel element (CCE) index with whichthe PDCCH is transmitted, or a combination of any of them.

In addition, the relative resource number may be assigned directly in aMAC CE and/or DCI.

Furthermore, a part of the relative resource number may be assigneddirectly in a MAC CE and/or DCI, and a remaining part may be determinedin the above described implicit manner.

On/off of frequency hopping at the time of Long PUCCH transmission maybe assigned semi-statically per terminal or per bandwidth part orcandidate band set for a terminal. Alternatively, dynamic assignment maybe done by including a flag indicating on/off of frequency hopping inDCI.

5. SECOND EXAMPLE EMBODIMENT

Next, the second example embodiment of the present disclosure isdescribed with reference to FIG. 15 and FIG. 16. The above describedfirst example embodiment is a specific example embodiment, while thesecond example embodiment is more generalized example embodiment.

<5.1. Configuration of Base Station>

With reference to FIG. 15, an example of a configuration of a basestation 100 according to the second example embodiment is described.FIG. 15 is a block diagram illustrating an example of a schematicconfiguration of the base station 100 according to the second exampleembodiment. According to FIG. 15, the base station 100 includes acommunication processing unit 150. Concrete operations of thecommunication processing unit 150 will be described later.

The communication processing unit 150 may be implemented by one or moreprocessors (a BB processor and/or other types of processors, and thelike) and a memory. The memory may be included in the one or moreprocessors, or may be outside of the one or more processors.

The base station 100 may include a memory storing a program(instructions), and one or more processors capable of executing theprogram (the instructions). The one or more processors may execute theprogram to perform the operations of the communication processing unit150. The program may be a program that causes a processor to execute theoperations of the communication processing unit 150.

Note that the base station 100 may be virtualized. In other words, thebase station 100 may be implemented as a virtualized machine. In thiscase, the base station 100 (the virtualized machine) may operate as avirtual machine on a physical machine (hardware) including a processorand a memory and a hypervisor.

Note that, of course, the base station 100 may further include aconstituent component other than the communication processing unit 150.For example, the base station 100 may further include a wirelesscommunication unit 110, a network communication unit 120 and/or astorage unit 130 as well as the first example embodiment, and/or mayfurther include other constituent components.

<5.2. Configuration of Terminal Apparatus>

With reference to FIG. 16, an example of a configuration of a terminalapparatus 200 according to the second example embodiment is described.FIG. 16 is a block diagram illustrating an example of a schematicconfiguration of the terminal apparatus 200 according to the secondexample embodiment. According to FIG. 16, the terminal apparatus 200includes a communication processing unit 240. Concrete operations of thecommunication processing unit 240 will be described later.

The communication processing unit 240 may be implemented by one or moreprocessors (a BB processor and/or other types of processors, and thelike) and a memory. The memory may be included in the one or moreprocessors, or may be outside of the one or more processors. As oneexample, the communication processing unit 240 may be implemented in aSoC.

The terminal apparatus 200 may include a memory storing a program(instructions), and one or more processors capable of executing theprogram (the instructions). The one or more processors may execute theprogram to perform operations of the communication processing unit 240.The program may be a program that causes a processor to execute theoperations of the communication processing unit 240.

Note that, of course, the terminal apparatus 200 may further include aconstituent component other than the communication processing unit 240.For example, the terminal apparatus 200 may further include a wirelesscommunication unit 210 and/or a storage unit 220 as well as the firstexample embodiment, and/or may further include other constituentcomponents.

<5.3. Technical Feature>

Technical features of the second example embodiment are described.

The base station 100 (the communication processing unit 150)communicates with a first terminal apparatus (the terminal apparatus200) in a bandwidth part of an uplink system band, the bandwidth partbeing used by the first terminal apparatus (the terminal apparatus 200),and the first terminal apparatus (the communication processing unit 240of the terminal apparatus 200) communicates with the base station 100 inthe bandwidth part. The bandwidth part includes a physical uplinkcontrol channel region used by the first terminal apparatus (theterminal apparatus 200).

For example, this enables the first terminal apparatus to transmit aphysical uplink control channel to the base station without retuningeven if bandwidth parts are different between terminal apparatuses. Morespecifically, it is possible for the first terminal apparatus totransmit a physical uplink control channel to a base station withoutretuning even if a maximum transmission bandwidth of the first terminalapparatus is small.

As one example, descriptions about a bandwidth part, a physical uplinkcontrol channel region and/or control information are the same as thedescriptions for the first example embodiment. Hence, overlappingdescriptions are omitted here. Note that, in this case, thecommunication processing unit 150 may operate as well as thecommunication processing unit 141 of the first example embodiment, andthe communication processing unit 240 may operate as well as thecommunication processing unit 231 of the first example embodiment.

Of course, the second example embodiment is not limited to theseexamples.

6. OTHER EXAMPLE ASPECTS

While the example embodiments of the present disclosure have beendescribed, the present disclosure is not limited to these exampleembodiments. It will be understood by those skilled in the art thatthese example embodiments are merely examples and various change can bemade without departing from the scope and the spirit of the presentdisclosure.

For example, an apparatus (e.g. one or more apparatuses (or units) outof a plurality of apparatuses (or units) constituting the base station,or a module for one of the plurality of apparatuses (or units))including constituent elements of the base station described herein(e.g. the communication processing unit and/or the information obtainingunit) may be provided. An apparatus (e.g. a module for the terminalapparatus) including constituent elements of the terminal apparatusdescribed herein (e.g. the communication processing unit) may beprovided. Moreover, methods including processing of such constituentelements may be provided, and programs for causing processors to executeprocessing of such constituent elements may be provided. Furthermore,non-transitory computer readable recording media having recorded thereonthe program may be provided. Of course, such apparatuses, modules,methods, programs and non-transitory computer readable recording mediaare also included in the present disclosure.

Some of or all the above-described example embodiments can be describedas in the following Supplementary Notes, but are not limited to thefollowing.

(Supplementary Note 1)

A base station comprising:

a communication processing unit configured to communicate with a firstterminal apparatus in a bandwidth part of an uplink system band, thebandwidth part being used by the first terminal apparatus,

wherein the bandwidth part includes a physical uplink control channelregion used by the first terminal apparatus.

(Supplementary Note 2)

The base station according to Supplementary Note 1, wherein

the bandwidth part includes a plurality of physical uplink controlchannel regions used by the first terminal apparatus, and

the plurality of physical uplink control channel regions are separatedfrom each other in frequency direction.

(Supplementary Note 3)

The base station according to Supplementary Note 1 or 2, wherein

the uplink system band includes a plurality of subbands, and

the bandwidth part includes one or more of the plurality of subbands.

(Supplementary Note 4)

The base station according to Supplementary Note 3, wherein each of theplurality of subbands includes a plurality of resource blocks contiguousin frequency direction.

(Supplementary Note 5)

The base station according to Supplementary Note 3 or 4, wherein thebandwidth part is one or more of the plurality of subbands.

(Supplementary Note 6)

The base station according to any one of Supplementary Notes 3 to 5,wherein the physical uplink control channel region is located within asubband included in the bandwidth part.

(Supplementary Note 7)

The base station according to Supplementary Note 6, wherein

the bandwidth part includes two or more subbands out of the plurality ofsubbands, and

the physical uplink control channel region is located within one subbandout of the two or more subbands included in the bandwidth part.

(Supplementary Note 8)

The base station according to Supplementary Note 7, wherein the physicaluplink control channel region is located within a subband at the edge ofthe two or more subbands.

(Supplementary Note 9)

The base station according to Supplementary Note 7 or 8, wherein

the bandwidth part includes a plurality of physical uplink controlchannel regions used by the first terminal apparatus,

the plurality of physical uplink control channel regions includes afirst physical uplink control channel region and a second physicaluplink control channel region separated from the first physical uplinkcontrol channel region in frequency direction,

the first physical uplink control channel region is located within onesubband out of the two or more subbands included in the bandwidth part,and

the second physical uplink control channel region is located within onesubband out of the two or more subbands included in the bandwidth part,the one subband being different from a subband within which the firstphysical uplink control channel region is located.

(Supplementary Note 10)

The base station according to Supplementary Note 7, wherein

the physical uplink control channel region is located within onecandidate band out of two or more candidate bands within the bandwidthpart, and

each of the two or more candidate bands is one subband within thebandwidth part, or two or more subbands contiguous in frequencydirection within the bandwidth part.

(Supplementary Note 11)

The base station according to any one of Supplementary Notes 7 to 10,wherein the physical uplink control channel region is located in apredetermined portion within the subband.

(Supplementary Note 12)

The base station according to Supplementary Note 11, wherein thepredetermined portion is a portion at the edge of the subband.

(Supplementary Note 13)

The base station according to Supplementary Note 11, wherein thepredetermined portion is a portion spaced from the edge of the subbandwith a predetermined gap.

(Supplementary Note 14)

The base station according to any one of Supplementary Notes 5 to 13,wherein the bandwidth part used by the first terminal apparatus includesone or more of subbands included in a bandwidth part used by a secondterminal apparatus different from the first terminal apparatus.

(Supplementary Note 15)

The base station according to any one of Supplementary Notes 1 to 14,wherein the communication processing unit is configured to transmit, tothe first terminal apparatus, first control information for specifyingthe physical uplink control channel region.

(Supplementary Note 16)

The base station according to Supplementary Note 15, wherein

the uplink system band includes a plurality of subbands,

the bandwidth part includes one or more of the plurality of subbands,

the physical uplink control channel region is located within a subbandincluded in the bandwidth part, and

the first control information is control information for specifying asubband within which the physical uplink control channel region islocated.

(Supplementary Note 17)

The base station according to Supplementary Note 16, wherein

the bandwidth part includes two or more of the plurality of subbands,

the physical uplink control channel region is located within onecandidate band out of two or more candidate bands within the bandwidthpart,

each of the two or more candidate subbands is one subband within thebandwidth part or two or more subbands contiguous in frequency directionwithin the bandwidth part,

the first control information is control information for identifying acandidate band within which the physical uplink control channel regionis located, and

the communication processing unit is configured to transmit, to thefirst terminal apparatus, second control information for specifying thetwo or more candidate bands.

(Supplementary Note 18)

The base station according to Supplementary Note 17, wherein thecommunication processing unit is configured to transmit, to the firstterminal apparatus, a media access control (MAC) control elementincluding the second control information.

(Supplementary Note 19)

The base station according to Supplementary Note 17, wherein thecommunication processing unit is configured to transmit, to the firstterminal apparatus, a radio resource control (RRC) message including thesecond control information.

(Supplementary Note 20)

The base station according to any one of Supplementary Notes 17 to 19,wherein the first control information is an index for identifying acandidate band from among a plurality of candidate bands within theuplink system band, the candidate band being a candidate band withinwhich the physical uplink control channel region is located.

(Supplementary Note 21)

The base station according to any one of Supplementary Notes 17 to 19,wherein the first control information is an index for identifying acandidate band from among the two or more candidate bands within thebandwidth part, the candidate band being a candidate band within whichthe physical uplink control channel region is located.

(Supplementary Note 22)

The base station according to Supplementary Note 20 or 21, wherein thecommunication processing unit is configured to transmit, to the firstterminal apparatus, downlink control information (DCI) including theindex.

(Supplementary Note 23)

The base station according to Supplementary Note 20 or 21, wherein thecommunication processing unit is configured to transmit, to the firstterminal apparatus, a media access control (MAC) control elementincluding the index.

(Supplementary Note 24)

A first terminal apparatus comprising:

a communication processing unit configured to communicate with a basestation in a bandwidth part of an uplink system band, the bandwidth partbeing used by the first terminal apparatus,

wherein the bandwidth part includes a physical uplink control channelregion used by the first terminal apparatus.

(Supplementary Note 25)

A method comprising:

communicating with a first terminal apparatus in a bandwidth part of anuplink system band, the bandwidth part being used by the first terminalapparatus,

wherein the bandwidth part includes a physical uplink control channelregion used by the first terminal apparatus.

(Supplementary Note 26)

A method comprising:

communicating with a base station in a bandwidth part of an uplinksystem band, the bandwidth part being used by the first terminalapparatus,

wherein the bandwidth part includes a physical uplink control channelregion used by the first terminal apparatus.

(Supplementary Note 27)

A program that causes a processor to execute:

communicating with a first terminal apparatus in a bandwidth part of anuplink system band, the bandwidth part being used by the first terminalapparatus,

wherein the bandwidth part includes a physical uplink control channelregion used by the first terminal apparatus.

(Supplementary Note 28)

A program that causes a processor to execute:

communicating with a base station in a bandwidth part of an uplinksystem band, the bandwidth part being used by the first terminalapparatus,

wherein the bandwidth part includes a physical uplink control channelregion used by the first terminal apparatus.

(Supplementary Note 29)

A non-transitory computer readable recording medium having recordedthereon a program that causes a processor to execute:

communicating with a first terminal apparatus in a bandwidth part of anuplink system band, the bandwidth part being used by the first terminalapparatus,

wherein the bandwidth part includes a physical uplink control channelregion used by the first terminal apparatus.

(Supplementary Note 30)

A non-transitory computer readable recording medium having recordedthereon a program that causes a processor to execute:

communicating with a base station in a bandwidth part of an uplinksystem band, the bandwidth part being used by the first terminalapparatus,

wherein the bandwidth part includes a physical uplink control channelregion used by the first terminal apparatus.

(Supplementary Note 31)

A system comprising:

a base station including a communication processing unit configured tocommunicate with a first terminal apparatus in a bandwidth part of anuplink system band, the bandwidth part being used by the first terminalapparatus; and

the first terminal apparatus including a communication processing unitconfigured to communicate with the base station in the bandwidth part,

wherein the bandwidth part includes a physical uplink control channelregion used by the first terminal apparatus.

This application claims priority based on Japanese Patent ApplicationNo. 2017-149247 filed on Aug. 1, 2017, the entire disclosure of which isincorporated Industrial Applicability

In a mobile communication system, it is possible for a first terminalapparatus to transmit a physical uplink control channel to a basestation without retuning regardless of a bandwidth part used by thefirst terminal apparatus.

REFERENCE SIGNS LIST

-   1 System-   100 Base Station-   200 Terminal Apparatus-   141, 150, 231, 240 Communication Processing Unit-   143 Information Obtaining Unit

What is claimed is:
 1. A method performed by a base station, the methodcomprising: transmitting, to a user equipment (UE), a radio resourcecontrol (RRC) message including first control information indicating afirst index, wherein the first index corresponds to a first offsetvalue; transmitting, to the UE, a Physical Downlink Control Channel(PDCCH), which corresponds to one or more control channel element(s)(CCE(s)), wherein a Downlink Control Information (DCI) format is carriedin the PDCCH; and receiving, from the UE, a Physical Uplink ControlChannel (PUCCH) including Hybrid Automatic Repeat Request(HARD)-Acknowledgement (ACK) information corresponding to the DCIformat, at a first position of a resource block, wherein the firstposition is located within an uplink bandwidth part in frequency domain,wherein the first position corresponds to the first offset value and anumber of resource blocks, which is based on a second index of a firstCCE of the one or more CCE(s), wherein the first offset value indicatesa first distance between a starting position of the uplink bandwidthpart and a second position, and wherein the number of resource blocksindicates a second distance between the second position and the firstposition.
 2. The method according to claim 1, wherein the first offsetvalue is one of a plurality of candidate values.
 3. The method accordingto claim 1, wherein the first index corresponds to the first offsetvalue according to a table that indicates a relationship between thefirst index and the first offset value.
 4. The method according to claim1, wherein the number of resource blocks is determined independent ofthe first control information.
 5. The method according to claim 1,wherein the PUCCH is received using frequency hopping, and the firstposition is either a resource block of the PUCCH in a first hop of thefrequency hopping or a resource block of the PUCCH in a second hop ofthe frequency hopping.
 6. The method according to claim 1, wherein thefirst position is determined by adding to the starting position of theuplink bandwidth part, the first offset value and the number of resourceblocks.
 7. The method according to claim 1, wherein the first offsetvalue is in first units of resource in frequency domain, the resource inthe first units being defined within the uplink bandwidth part infrequency domain and numbered from 0 to (a first value −1), and whereinthe first value is a size of the uplink bandwidth part.
 8. The methodaccording to claim 1, wherein the starting position of the uplinkbandwidth part corresponds to a second offset from a starting positionof a carrier bandwidth.
 9. The method according to claim 1, wherein theuplink bandwidth part is located within a carrier bandwidth.
 10. Amethod performed by a user equipment (UE), the method comprising:receiving a radio resource control (RRC) message including first controlinformation indicating a first index; receiving a Physical DownlinkControl Channel (PDCCH), which corresponds to one or more controlchannel element(s) (CCE(s)); wherein a Downlink Control Information(DCI) format is received in the PDCCH; determining a first offset valuebased on the first index; determining a number of resource blocks, basedon a second index of a first CCE of the one or more CCE(s); determininga first position of a resource block of a Physical Uplink ControlChannel (PUCCH) transmission based on the first offset value and thenumber of resource blocks; and performing the PUCCH transmission,wherein the PUCCH transmission includes Hybrid Automatic Repeat Request(HARD)-Acknowledgement (ACK) information corresponding to the DCIformat, wherein the first position is located within an uplink bandwidthpart in frequency domain, wherein the first offset value indicates afirst distance between a starting position of the uplink bandwidth partand a second position, and wherein the number of resource blocksindicates a second distance between the second position and the firstposition.
 11. The method according to claim 10, wherein the first offsetvalue is one of a plurality of candidate values.
 12. The methodaccording to claim 10, wherein the first index corresponds to the firstoffset value according to a table that indicates a relationship betweenthe first index and the first offset value.
 13. The method according toclaim 10, wherein the number of resource blocks is determinedindependent of the first control information.
 14. The method accordingto claim 10, wherein the PUCCH transmission is performed using frequencyhopping, and the first position is either a resource block of the PUCCHtransmission in a first hop of the frequency hopping or a resource blockof the PUCCH transmission in a second hop of the frequency hopping. 15.The method according to claim 10, wherein the first position isdetermined by adding to the starting position of the uplink bandwidthpart, the first offset value and the number of resource blocks.
 16. Themethod according to claim 10, wherein the first offset value is in firstunits of resource in frequency domain, the resource in the first unitsbeing defined within the uplink bandwidth part in frequency domain andnumbered from 0 to (a first value −1), and wherein the first value is asize of the uplink bandwidth part.
 17. The method according to claim 10,wherein the starting position of the uplink bandwidth part correspondsto a second offset from a starting position of a carrier bandwidth. 18.The method according to claim 10, wherein the uplink bandwidth part islocated within a carrier bandwidth.
 19. A base station comprising: atransmitter configured to: transmit to a user equipment (UE), a radioresource control (RRC) message including first control informationindicating a first index, wherein the first index corresponds to a firstoffset value; and transmit, to the UE, a Physical Downlink ControlChannel (PDCCH), which corresponds to one or more control channelelement(s) (CCE(s)), wherein a Downlink Control Information (DCI) formatis carried in the PDCCH; and a receiver configured to receive, from theUE, a Physical Uplink Control Channel (PUCCH) including Hybrid AutomaticRepeat Request (HARD)-Acknowledgement (ACK) information corresponding tothe DCI format, at a first position of a resource block, wherein thefirst position is located within an uplink bandwidth part in frequencydomain, wherein the first position corresponds to the first offset valueand a number of resource blocks, which is based on a second index of afirst CCE of the one or more CCE(s), wherein the first offset valueindicates a first distance between a starting position of the uplinkbandwidth part and a second position, and wherein the number of resourceblocks indicates a second distance between the second position and thefirst position.
 20. The base station according to claim 19, wherein thenumber of resource blocks is determined independent of the first controlinformation.